Antipseudomonal monotherapy or combination therapy for older adults with community-onset pneumonia and multidrug-resistant risk factors: a retrospective cohort study

Obiageri O. Obodozie-Ofoegbu, Chengwen Teng, Eric M. Mortensen, Chris Frei

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    Background: Infectious Diseases Society of America guidelines recommend empiric antipseudomonal combination therapy when Pseudomonas is suspected. However, combination antipseudomonal therapy is controversial. This study compares all-cause 30-day mortality in older patients who received antipseudomonal monotherapy (PMT) or antipseudomonal combination therapy (PCT) for the treatment of community-onset pneumonia. Methods: This population-based, retrospective cohort study used data from over 150 Veterans Health Administration hospitals. Patients were classified as being at low, medium, or high risk of drug-resistant pathogens. In total, 31,027 patients were assigned to PCT or PMT treatment arms based on antibiotics received in the first 48hours of hospital admission. Results: The unadjusted 30-day mortality difference between PCT and PMT was most pronounced in the low-risk group (18% vs 8%), followed by the medium-risk group (24% vs 18%) and then the high-risk group (39% vs 33%). PCT was associated with higher 30-day mortality than PMT overall (adjusted odds ratio [aOR], 1.54; 95% confidence interval [CI], 1.43-1.66) in all 3 risk groups: low (aOR, 1.69; 95% CI, 1.50-1.89), medium (aOR, 1.30; 95% CI, 1.14-1.48), and high (aOR, 1.21; 95% CI, 1.04-1.40). Conclusions: Older adults who received combination antipseudomonal therapy for community-onset pneumonia fared worse than those who received monotherapy. Empiric combination antipseudomonal therapy should not be routinely offered to all patients suspected of having pseudomonal pneumonia.

    Original languageEnglish (US)
    JournalAmerican Journal of Infection Control
    StatePublished - Jan 1 2019



    • Antibiotics
    • Mortality
    • Pseudomonas
    • Risk score
    • Survival

    ASJC Scopus subject areas

    • Epidemiology
    • Health Policy
    • Public Health, Environmental and Occupational Health
    • Infectious Diseases

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